Originally Posted by Professor Shadow
In the example you show here are the numbers.

The top line represents how many watts are being used, that is the total power of everything you have plugged in.
Once you have the total power drain on the UPS (batteries) the second line tell you how long until the UPS will last (under optimum conditions)


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For a example, most hair dryers draw 1500 watts. If you look up 1500 watts...oops not enough power.

Another example: My laptop draws 120 watts, so that would be just under 7-1/2 hours. Great...oops forgot the Modem...and the Wireless Router...hope I don't need to print anything!

So, you can see how it all affects the length of time you can stay on-line.
Thankyou for this chart. what I would need this for is telephone only, as I have nothing but VoIP and during the event of a power outage I would have only one phone (a western electric 2500) and a digital to analogue converter(an obihai200) so I would just be needing backup for this only for the duration of the power outage as anything else would drain the battery life so thats what I would need to figure out i guess is one obihai200 box and one 2500 telephone as well as the modem thank you for your help

Last edited by Southernphoneman; 08/26/19 05:26 PM.